1. Field of the Invention
The present invention is related to a control apparatus for a printer, particularly to a suspension control of the print.
2. Description of the Prior Art
Generally speaking, a printing speed by a printer is rather slow when compared with a transmitting speed of data from a data processor such as a host computer to the printer. In order to speed up the printing speed, there is provided a buffer of large capacity for storing data in a printer. Namely, data sent to the printer are stored in said buffer temporarily and the printer carries out a print of data by reading out data stored in said buffer successively.
In the case that such a buffer as mentioned above is not provided in the printer, there is employed such a system in that a buffer of large capacity is interposed between the printer and the data processor.
Meanwhile, in case of a transmission error caused upon transmitting data from the data processor such as a misidentification of a file or in case a jamming is caused in the printer, the data transmission from the data processor can be suspended at once.
However, since the printing operation regarding data having been memorized in the buffer of the printer or the external buffer cannot be suspended at once, an unnecessary print is carried out. Further, in the case of printing a graphic image, a user must wait a long time until an unnecessary print has been finished even if the suspension of print was commanded. Although there may be considered a method in which the power supply to the printer is cut off forcibly at that time, data sent by another data processor or data made by another users are deleted at the same time in the case wherein a plurality of data processors are connected thereto or files of other users are stored in the buffer. This problem regarding the suspension of the printer becomes more serious as the capacity of the buffer becomes large.
Further, in a conventional printer, only a function for cancelling data being printed at the moment is provided and, therefore, it is impossible to suspend the print of individual pages or files (groups of pages) and/or all files.